JP2008068370A - Adjustable type chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adjustable type chuck which has a simple structure utilizing a general purpose type chuck, and allows adjustment of the mounting position of soft jaws for gripping a workpiece in the radial direction, and is excellent in profitability. <P>SOLUTION: The chuck has top fingers mounted on a plurality of master jaws so as to grip the workpiece, wherein the master jaws are arranged on the front surface of a chuck body at nearly equiangular positions, and slide in the radial direction. The chuck makes the master jaws reciprocate in the radial direction together with the top fingers by means of a driving mechanism. The top fingers are formed so as to have a two layer structure composed of chuck bases to be fixed to the master jaws and soft jaws which are connected to the chuck bases by means of serrations, and are dismountably mounted on the chuck bases by means of fixing bolts, and grip the workpiece. In addition, guiding mechanisms slidable in the radial direction are arranged between the chuck bases and the soft jaws. The soft jaws are mounted so as to adjust the mounting position in the radial direction with respect to the chuck bases by means of the guiding mechanisms and the fixing bolts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chuck for gripping a workpiece (workpiece) to be cut and attached to a spindle of a machine tool, and in particular, a raw claw (clamp claw) for gripping a workpiece has a radius with respect to the spindle. The present invention relates to an adjustable chuck that is mounted so that its mounting position in the direction can be adjusted.

  Conventionally, as a chuck means for supporting a workpiece that is attached to a main spindle of a machine tool and performs machining or the like, the eccentric amount (adjustment amount) of the chuck position with respect to the rotation center axis of the main spindle can be made variable. There is known an eccentric chuck similar to the adjustable chuck.

  As an example of such an eccentric chuck, a chuck device in which a conventional three-jaw power chuck is improved has been proposed (see Patent Document 1).

  In the chuck device described in Patent Document 1, three master jaws are mounted on the front surface of the chuck body at 120 ° intervals so as to be slidable in the radial direction, and each master jaw has a top for gripping a workpiece. In the power chuck in which the jaws are respectively mounted and the master jaw is moved by the same amount in the direction of approaching or moving away together with the top jaw by a drive mechanism built in the chuck body, the top jaw is supported by the supporting member and the gripping member. It is formed in a two-layer structure, and the dimensional form of the workpiece gripping surface formed on the gripping member of one top jaw and the workpiece gripping surface formed on the remaining two top jaw gripping members are different. Each of the two top jaws is attached to the supporting member so as to hold the gripping member so that it can be turned over. It is configured so that. Thus, the work can be held eccentrically by attaching the gripping members of the two top jaws upside down.

  On the other hand, there has been proposed an eccentric chuck that can easily perform the positioning operation of the workpiece to be processed to the eccentric position and can easily and easily cope with the change of the eccentric position of the workpiece to be processed (patent) Reference 2).

The eccentric chuck described in Patent Document 2 is provided with a clamp boss for providing a plurality of clamp claws so as to be radially deformed in a cylindrical direction on the outer peripheral portion of the cylindrical outer periphery, and to the clamp boss in the center direction. It consists of a plurality of clamp claws that are mounted so as to be able to advance and retreat, respectively, and hold the workpiece in an eccentric position, and a clamped ring that is placed on the outer periphery of the clamp boss and holds the clamp boss so that it can be pressed and deformed. The outer periphery of the end presser ring is fixedly held by a chuck member mounted on a required machine tool, and the work held by a plurality of clamp claws attached to the clamp boss is held in an eccentric position. .
Japanese Patent Laid-Open No. 62-241604 JP 2004-130503 A

  However, in the chuck device described in Patent Document 1, in order to hold the work in an eccentric manner, the dimensional form with the work gripping surface formed on the gripping members of the two top jaws is different. Since the top jaws are configured to move the same amount in the direction of approaching or moving away all at once, the amount of eccentricity (adjustment amount) of the workpiece is constant, and the amount of eccentricity (adjustment amount) can be changed arbitrarily Can not. In order to change the amount of eccentricity (adjustment amount), it is necessary to prepare a number of top jaws with different dimensional forms of the workpiece gripping surface separately formed on the gripping member. There are problems such as getting worse.

  On the other hand, the eccentric chuck described in Patent Document 2 improves the problem in Patent Document 1 and can easily perform the positioning operation of the workpiece to be processed to the eccentric position, and instantaneously moves the workpiece positioned at the eccentric position. The machine tool can be machined immediately, and continuous machining of the same workpiece can be easily realized, and the eccentric position of the workpiece can be changed easily and easily. It has been improved to be able to. However, a clamp boss with a radial cut in the cylindrical outer periphery, a plurality of clamp claws attached to the clamp boss so as to be able to advance and retreat in the center direction, a clamped ring that holds the clamp boss so that it can be pressed and deformed, etc. There exists a problem that the structure which consists of becomes a complicated structure completely different from the existing general purpose type | mold chuck | zipper. Therefore, it is impossible to expect the convenience and economy of constructing an adjustable chuck by using an existing general-purpose chuck as in Patent Document 1.

  The present invention has been made to solve such a conventional problem, and has a simple structure using an existing general-purpose chuck, and the mounting position of the raw claw for gripping the workpiece is in the radial direction with respect to the main shaft. It is an object of the present invention to provide an adjustable chuck that can be easily adjusted and is excellent in economic efficiency and workability.

  In order to achieve the above object, an adjustable chuck according to a first aspect of the present invention includes a plurality of master jaws disposed at substantially equal angles on a front surface of a chuck body so as to be slidable in a radial direction. The top finger has fine serrations on the surface of the chuck where the master jaw is mounted with a top finger for gripping the workpiece and the master jaw is reciprocated with the top finger in the radial direction by the drive mechanism built in the chuck body. The chuck base fixed to the master jaw and the raw claws that are serrated to the chuck base via fine serrations formed on the back surface and are detachably mounted by fixing bolts to hold the workpiece are respectively identical. The chuck base and the raw A guide mechanism that is slidable in the radial direction is provided between the chuck and the raw claw so that the radial mounting position can be adjusted relative to the chuck base by the guide mechanism and the fixing bolt. Features.

  The invention according to claim 2 is the adjustable chuck according to claim 1, wherein the guide mechanism is formed by a guide rod projecting from a central portion of the surface of the chuck base and a radial nail in the raw nail. And a long hole formed to be slidable by fitting the guide rod.

  A third aspect of the present invention is the adjustable chuck according to the first aspect, wherein the guide mechanism includes a dovetail groove formed along a radial direction on the surface side of the chuck base, and fitted into the dovetail groove. The sliding piece is formed so as to be slidable, and the raw claw is mounted by the fixing bolt.

  According to the first aspect of the present invention, a top finger having a two-layer structure of a chuck base and a raw claw is attached to the master jaw of the chuck, and the raw claw is moved in a radial direction relative to the chuck base by the guide mechanism and the fixing bolt. Since the mounting position can be adjusted in a simple structure, the existing general-purpose chuck can be used in a simple structure, and the mounting position of the raw claw that grips the workpiece can be adjusted in the radial direction with respect to the spindle. It is possible to provide an adjustable type chuck that is excellent at low cost.

  In particular, in the case of an inward opening chuck that grips the inner diameter of the workpiece, an integrated raw claw that is processed into a partial cylindrical shape so that the tip fits the inner diameter of the workpiece is used. For fixed chucks where the radial mounting position cannot be adjusted, each time the inner diameter of the workpiece changes, it is necessary to replace it with a new nail that has been processed into a shape that fits another inner diameter, which is very inconvenient and economical. . When the adjustable chuck according to the present invention is applied to such an inner opening chuck, it is possible to easily cope with a workpiece in which the inner diameter of the gripping portion is changed, and it is possible to achieve more excellent effects in terms of workability and economy.

  According to the invention of claim 2, in addition to having the same effect as that of the invention of claim 1, the guide rod is fitted to the guide rod and the raw claw protruding from the surface of the chuck base. By adopting a simple structure consisting of elongated holes slidable along the radial direction, the chuck base is lowered and the rigidity of the double-structured top finger is assured as that of a general-purpose standard chuck. As a result, large workpieces can be processed stably.

  According to the invention of claim 3, in addition to having the same effect as that of the invention of claim 1, the guide mechanism is fitted in the dovetail groove formed in the radial direction of the chuck base and the dovetail groove. By making it a structure that consists of a sliding piece that is formed to be slidable and attaches the raw claws with fixing bolts, the amount of movement of the raw claws relative to the chuck base can be increased, and it can accommodate workpieces of various grip sizes Therefore, it is possible to achieve more excellent effects in terms of convenience and economy. Further, since the height of the chuck base is increased by providing the dovetail groove, there is an effect that a relatively long workpiece can be gripped and processed.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 11 is a conceptual diagram of a known chuck with the top finger removed, (a) is a plan view (front view), and (b) is a side view of (a).

  A known chuck has, for example, three substantially inverted T-shaped (or not illustrated) cross-shaped antlets formed on the front surface of a cylindrical chuck body 1 in a radial direction with a substantially equal angle, for example, 120 ° apart from each other. A master jaw 2 is slidably fitted in the groove 1a, and a top jaw (not shown) for gripping a workpiece is attached to each master jaw 2 and transmitted from a power transmission member penetrating the spindle of the machine tool. Or a driving force generated by a fluid pressure actuator such as air is transmitted to the master jaw 2 via a driving mechanism (not shown) built in the chuck body 1, and the master jaw 2 along with the top jaw along the dovetail groove 1a. At the same time, it is structured to move in the direction of approaching or moving away (expanding / reducing diameter in the radial direction). A top jaw (not shown) is fitted to the master jaw 2 by fitting with, for example, three fixing pins 3 provided on the master jaw 2 and projecting, for example, by screwing fixing bolts (not shown) into two screw holes 2a and tightening. Fixed.

  1A and 1B are conceptual diagrams of an adjustable chuck according to a first embodiment of the present invention. FIG. 1A is a plan view (front view) and FIG. 1B is a side view of FIG.

  The adjustable chuck according to the first embodiment of the present invention includes a chuck base 4 on which top fingers 10 attached to, for example, three master jaws 2 of the known general-purpose chuck as described above are fixed to the master jaw 2; The chuck base 4 has a two-layer structure including a raw claw (clamp claw) 5 that is serrated to the chuck base 4 and is detachably mounted by a fixing bolt 6 to grip a workpiece, and each has the same shape. A guide mechanism 20 is provided between the chuck base 4 and the raw claw 5 so as to be slidable in the radial direction. The raw claw 5 is mounted in the radial direction relative to the chuck base 4 by the guide mechanism 20 and the fixing bolt 6. The position is adjustable. The guide mechanism 20 will be described later.

  2A is a plan view (surface view) of the chuck base 4 in FIG. 1, FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A, and FIG. 2C is a view taken along the line BB in FIG. It is sectional drawing.

  As shown in FIG. 2A, the chuck base 4 has a substantially rectangular plane, and a rear end (left side in the drawing) surface 4f is formed in a cylindrical surface substantially equal to the radius R of the chuck body 1 and has a longitudinal direction on the surface. A fine serration 4a having a substantially triangular tooth cross section is formed except for the flat groove 4e (FIG. 2C) provided along the central axis (in the radial direction of the chuck body 1). Further, as shown in FIGS. 2A and 2B, the fixing pin hole 4b into which the fixing pin 3 (FIGS. 1B and 11) is fitted at the center and both ends along the central axis in the longitudinal direction. And a bolt hole 4c through which the fixing bolt 6 (FIG. 1) is inserted is provided between the fixing pin holes 4b. Further, as shown in FIGS. 2B and 2C, a guide rod fixing hole 4d into which the guide rod 7 (FIG. 1) is press-fitted and fixed above the fixing pin hole 4b in the center is substantially concentric. Is formed.

  As shown in FIG. 1B, the chuck base 4 has a flat back surface side aligned with the upper surface of the master jaw 2 and a fixing pin 3 provided on the master jaw 2 and protruding from the fixing pin hole 4b. Fixed to master jaw 2.

  3 (a) is a plan view (front view) of the raw nail 5 of FIG. 1, FIG. 3 (b) is a side view of FIG. 4 (a), FIG. 4 (a) is a back view of FIG. FIG. 3B is an enlarged view of a portion C in FIG.

  As shown in FIG. 3A, the raw nail 5 has a substantially rectangular flat surface, and a tapered surface 5d having an opening angle θ1, for example, θ1 = 120 ° is formed by cutting both ends of the tip (right side in the drawing), and on the back surface. Fine serrations 5a having a substantially triangular tooth shape in cross section are formed except for the flat step portion 5e (FIG. 3C) provided at the tip (right side in the figure). In addition, a long hole 5b is formed which is slidable by fitting the guide rod 7 (FIG. 1) slightly toward the rear end (left side in the figure) along the central axis in the longitudinal direction (radial direction of the chuck body 1). In addition, a counterbore 5c is formed along the periphery of the long hole 5b to which the head of the fixing bolt 6 (FIG. 1) is seated.

  The raw claws 5 are serrated and joined with the back side on which the fine serrations 5a are formed aligned with the upper surface of the chuck base 4, and at the same time, the chuck base 4 is inserted into the elongated hole 5b as shown in FIGS. The guide rod 7 protruding upward is fitted and fixed to the master jaw 2 together with the chuck base 4 by screwing and tightening the fixing bolt 6 into, for example, two screw holes 2a (FIG. 11) of the master jaw 2. .

  As shown in FIGS. 2B and 4B, the serrations 4a and 5a formed on the chuck base 4 and the raw claws 5 have the same shape, for example, a pitch p = 1 mm having a triangular tooth profile. A tooth having a tooth height h = 0.866 mm and a tooth surface angle θ = 60 ° is formed.

  In this embodiment, the guide mechanism 20 projects from the guide rod 7 protruding from the surface of the chuck base 4 and the elongated hole 5b formed so that the guide rod 7 is fitted to the raw claw 5 and is slidable in the radial direction. Thus, the raw claws 5 can be adjusted by shifting the mounting position in the radial direction with respect to the main spindle of the machine tool every serration tooth pitch p (for example, p = 1 mm) in accordance with the size of the gripping portion of the workpiece (not shown). it can. The raw claw 5 is fixed to the master jaw 2 together with the chuck base 4 by tightening the fixing bolt 6 after adjusting the radial mounting position by sliding along the guide mechanism 20. Thereafter, when the radial mounting position of the raw claw 5 is adjusted again, the fixing bolt 6 is loosened, the raw claw 5 is slid along the guide mechanism 20 to a predetermined position in the radial direction, and then the fixing bolt 6 is tightened. Fix to master jaw 2. As a result, the top finger 10 including the chuck base 4 and the raw claws 5 is fixed to the master jaw 2.

  Thus, the mounting position of the raw claw 5 for gripping the workpiece can be achieved with a simple structure using the existing general-purpose chuck by the guide mechanism 20 and the fixing bolt 6 having a simple structure including the guide rod 7 and the long hole 5b. An adjustable chuck that is adjustable in the radial direction with respect to the main shaft and has excellent workability can be provided at low cost.

  FIGS. 5A and 5B are conceptual diagrams of an adjustable chuck according to Embodiment 2 of the present invention. FIG. 5A is a plan view (front view) and FIG. 5B is a side view of FIG.

  The adjustable chuck according to the second embodiment of the present invention is different from the first embodiment in the structure of the top finger and the guide mechanism. That is, the adjustable chuck according to the second embodiment includes a chuck base 41 to which the top fingers 11 attached to, for example, three master jaws 2 of a known general-purpose chuck similar to the first embodiment are fixed to the master jaw 2. The chuck base 41 has a two-layer structure including a raw claw (clamp claw) 51 that is serrated to the chuck base 41 and is detachably mounted by a fixing bolt 62 to grip a workpiece, and is formed in the same shape. In addition, a guide mechanism 21 having a sliding piece 8 slidable in the radial direction is provided between the chuck base 41 and the raw claw 51, and the raw claw 51 is made relative to the chuck base 41 by the guide mechanism 21 and the fixing bolt 62. Thus, the mounting position in the radial direction can be adjusted. The guide mechanism 21 will be described later.

  6A is a plan view (surface view) of the chuck base 41 of FIG. 5 (Example 2), FIG. 6B is a side view of FIG. 6A, and FIG. 7A is FIG. A rear view (left side view in the figure) and FIG. 7B are enlarged views of a portion D in FIG. 6B.

  As shown in FIG. 6A, the chuck base 41 has a substantially rectangular plane, and has a tapered surface 41e having an opening angle θ1, for example, θ1 = 120 °, with both ends of the tip (right side in the figure) cut, and a surface. In the longitudinal direction (radial direction of the chuck body 1), for example, a dovetail groove 41f (FIG. 7 (a)) having a substantially inverted T-shape in cross section and a flat step portion 41g provided at the tip portion are formed. Except for that, a fine serration 41a having a substantially triangular tooth cross section is formed. Further, as shown in FIGS. 6A and 6B, the fixing pin hole 41b into which the fixing pin 3 (FIGS. 5B and 11) is fitted at the center and both ends along the longitudinal central axis. Are provided, and for example, two bolt holes 41c through which the fixing bolts 61 (FIG. 1B) are inserted are provided between the fixing pin holes 41b. Further, counterbore 41d on which the head of fixing bolt 61 (FIG. 5B) is seated is formed concentrically at the upper part of bolt hole 41c.

  As shown in FIG. 5B, the chuck base 41 has a flat back surface side aligned with the upper surface of the master jaw 2, and the fixing pin 3 provided on the master jaw 2 and protruding from the fixing pin hole 41b is fitted, The fixing bolt 61 is screwed into the two screw holes 2a (FIG. 11) of the master jaw 2 and tightened to fix the master jaw 2.

  8A is a plan view (front view) of the sliding piece 8 in FIG. 5, FIG. 8B is a side view of FIG. 5A, and FIG. 8C is a rear view of FIG. is there.

  The sliding piece 8 is substantially rectangular in plan as shown in FIG. 8A, and is slidably fitted in the dovetail groove 41f of the chuck base 41 as shown in FIGS. 5B and 7A. The cross section is formed in a substantially inverted T-shape composed of a convex portion 8a and a base portion 8b so as to match. The upper part of the convex portion 8a of the sliding piece 8 is set so as to slightly protrude from the upper surface of the chuck base 41 by about 1.5 mm, for example. Further, for example, two screw holes 8c into which the fixing bolts 62 (FIG. 5B) are screwed are formed along the center portion in the longitudinal direction (radial direction of the chuck body 1).

  The dovetail groove 41f and the sliding piece 8 of the chuck base 41 can be formed to have a substantially cross-shaped cross section that can slide relative to each other. However, the height of the both is kept low and the top finger 11 has sufficient rigidity. In order to ensure, it is preferable to form in the said substantially reverse T shape.

  9A is a plan view (surface view) of the raw nail 51 of FIG. 5 (Example 2), FIG. 9B is a side view of FIG. 9A, and FIG. 10A is FIG. 9B. FIG. 10B is an enlarged view of a portion E in FIG. 9B.

  As shown in FIG. 9 (a), the raw nail 51 has a substantially rectangular plane, a tapered surface 51d having an opening angle θ1 of 120 °, for example, 120 ° is formed by cutting both ends of the tip (right side in the figure), and the longitudinal direction of the back surface. A fine serration 51a having a substantially triangular tooth cross section is formed except for the flat groove 51e (FIG. 10A) provided along the central axis (radial direction of the chuck body 1). A bolt hole 51b through which the fixing bolt 62 (FIG. 1) is inserted is formed slightly along the central axis in the longitudinal direction (radial direction of the chuck body 1) slightly toward the rear end (left side in the figure). A counterbore 51c on which the head of the fixing bolt 62 is seated is formed concentrically at the top.

  The raw claws 51 are serrated and joined with the back side on which the fine serrations 51a are formed aligned with the upper surface of the chuck base 41, as shown in FIGS. 5 (a), 5 (b), 8 (c) and 10 (a). At the same time, the upper portion of the convex portion 8a of the sliding piece 8 protruding on the chuck base 41 is fitted into the flat groove 51e, and the fixing bolt 62 is screwed into the two screw holes 8c of the sliding piece 8. By being tightened, the chuck base 4 is fixed via the sliding piece 8. When the fixing bolt 62 is tightened at this time, the upper surface 8d of the base 8b of the sliding piece 8 is attracted to the upper surface 41h of the dovetail groove 41f of the chuck base 41 as shown in FIG. The raw claw 51 is fixed to the chuck base 4.

  As shown in FIGS. 7B and 10B, the serrations 41a and 51a formed on the chuck base 41 and the raw nail 51 have the same shape, for example, a pitch p = 1 mm having a triangular tooth profile. A tooth having a tooth surface angle θ = 60 ° is formed.

  In this embodiment, the guide mechanism 21 comprises a dovetail groove 41f formed on the surface of the chuck base 41 and a sliding piece 8 which is fitted in the dovetail groove 41f and is slidable along the radial direction. The raw claws 51 are adjusted by shifting the mounting position in the radial direction with respect to the spindle of the machine tool by the pitch p (for example, p = 1 mm) of the serrations 41a and 51a in accordance with the size of the workpiece gripping portion (not shown). can do. The raw claw 51 is fixed to the chuck base 41 via the sliding piece 8 by tightening the fixing bolt 62 after adjusting the radial mounting position by sliding with the guide mechanism 21. Thereafter, when the radial mounting position of the raw claw 51 is adjusted again, the fixing bolt 62 is loosened, the raw claw 51 is slid to the predetermined radial position by the guide mechanism 21, and then the fixing bolt 62 is tightened to tighten the chuck base. 41 is fixed. As a result, the top finger 11 including the chuck base 41 and the raw claws 51 is fixed to the master jaw 2.

  Also in this embodiment, the simple claw structure 41 using the dovetail 41f and the sliding piece 8 and the fixing bolt 62 allow the raw claw 51 to grip the workpiece with a simple structure using an existing general-purpose chuck. It is possible to provide an adjustable chuck that can adjust the mounting position in the radial direction with respect to the main shaft and has excellent workability at low cost.

  As described above, according to the present invention, the conventional problems described above are improved, and a simple structure using an existing general-purpose chuck is used. Thus, it is possible to provide an adjustable chuck that can be adjusted in the radial direction and is excellent in economic efficiency and workability.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram of the adjustable chuck | zipper of Example 1 of this invention, (a) is the top view (front view), (b) is a side view of (a). (A) is a plan view (surface view) of the chuck base of FIG. 1, (b) is a cross-sectional view taken along the line AA of (a), and (c) is a cross-sectional view taken along the line BB of (a). . (A) is a top view (surface view) of the raw nail | claw of FIG. 1, (b) is a side view of (a). (A) is a back view of FIG. 3 (a), (b) is an enlarged view of the C section of FIG. 3 (b). It is a conceptual diagram of the adjustable chuck | zipper of Example 2 of this invention, (a) is the top view (front view), (b) is a side view of (a). (A) is a top view (surface view) of the chuck base of FIG. 5, and (b) is a side view of (a). FIG. 6A is a rear view of FIG. 6B, and FIG. 6B is an enlarged view of a portion D in FIG. (A) is a plan view (surface view) of the sliding piece of FIG. 5, (b) is a side view of (a), and (c) is a rear view (left side view in the figure) of (b). (A) is a top view (surface view) of the raw nail | claw of FIG. 5, (b) is a side view of (a). FIG. 9A is a rear view (left side view in the drawing) of FIG. 9B, and FIG. 9B is an enlarged view of a portion E in FIG. 9B. It is a conceptual diagram of the well-known chuck | zipper of the state which removed the top finger, (a) is the top view (front view), (b) is a side view of (a).

Explanation of symbols

1 Chuck body 1a, 41f Dovetail groove 2 Master jaw 2a Screw hole 3 Fixing pin 4, 41 Chuck base 4a, 5a, 41a, 51a Serration 4b, 41b Fixing pin hole 4c, 41c, 51b Bolt hole 4d Guide rod fixing hole 4e, 51e Flat groove 4f Rear end face 5, 51 Raw claw (clamp claw)
5b Slot 5c Counterbore 5d, 41e, 51d Tapered surface 5e, 41g Step 6, 61, 62 Fixing bolt 7 Guide rod 8 Slide piece 8a Convex 8b Base 10, 11 Top finger 41d, 51c Counterbore p Pitch h Tooth height θ Tooth surface angle θ1 (Taper surface) opening angle

Claims (3)

A plurality of master jaws arranged at approximately the same angle on the front surface of the chuck body are slidably mounted in the radial direction, and top fingers for gripping workpieces are respectively mounted on the master jaws and incorporated in the chuck body. In the chuck for reciprocating the master jaw together with the top finger in the radial direction by the driven mechanism,
The top finger is formed with fine serrations on the front surface and fixed to the master jaw, and the top finger is serrated to the chuck base via fine serrations formed on the back surface, and is detachably mounted by fixing bolts. It is formed in the same shape in the two-layer structure with the raw nail to be gripped,
A guide mechanism capable of sliding in the radial direction is provided between the chuck base and the raw claw,
The adjustable type chuck is characterized in that the raw claw is mounted so that a radial mounting position can be adjusted relative to the chuck base by the guide mechanism and the fixing bolt. The guide mechanism is
A guide rod protruding from the center of the surface of the chuck base;
The adjustable chuck according to claim 1, comprising an elongated hole formed in the raw nail along a radial direction and formed to be slidable by fitting the guide rod. The guide mechanism is
Dovetails drilled along the radial direction of the surface side of the chuck base;
2. The adjustable chuck according to claim 1, further comprising a sliding piece fitted into the dovetail groove so as to be slidable and mounting the raw claw with the fixing bolt.

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